Telephone system



W. P. ALBERT TELEPHONE SYSTEM June 9, 1925.

2 Sheets-Sheet -71 Filed Aug. 31, 19255 In I I I H- June 9, 1925. 1,541,308

' w. P. ALBERT TELEPHONE SY2TEM-,

Filed Aug. 3 ,1925 Z SheetS-Sheet 2 Myen/af: Wa/frP/I/ber/ by 6 W/l/fj Jane 3, 1925.

users sra'ra lenses 5 Parent oi rica.

'WALTER P. ALBERT, OF EAST ORANGE, NEW" JERSEY, ASSIGNOB TO VTESTERN ELEC- TRIC COMPANY, INCGEPQEATED, G1? NEW YORK, N.

A. CGR POB ATION OF NEW TELEPHONE SYSTEM.

Application filed. August 31, 1923. Serial No. 660,284.

To all whom it may concern:

Be it known that I, WALTER P. ALBERT, a citizen of the United States of America, residing at East Orange, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in Telephone Systems, of which the tollowingis a full, clear, concise, and exact description.

tems.

In a telephone system wherein trunk circuits are employed between a main exchange and a. private branch exchange, it is necessary that metering mechanism be provided for the purpose o1 counting the number of calls outgoing from the private branch exchange so that a charge may be made therefor.

Heretotore the counting of such outgoing calls has been accomplished through the manual operation of a contact by the attendant at the private branch exchange.

Such a method of counting the calls is unreliable as the attendant may fail to count some calls or the counter so operated may indicate more calls than have actually been made.

It is an object of this invention therefore to provide a telephone system wherein the calls outgoing over a trunk circuitfrom a private branch exchange are automatically registered by a metering device.

Since the calls incoming to the private branch exchange should not be registered, the operation of the metering device on in coming calls must be prevented.

Another object of the invention therefore is to render the metering device effective to register calls, on a two-way trunk circuit, in one direction only.

This object is attained by the provision of means in a trunk circuit which discriminates between calls incoming to, and outgoing from a telephone exchange to selectively operate a message registering device.

Another feature oi the invention resides in the provision of means for preventing the false operation of the message registering device.

The above and other features of this in vention will readily appear from the following detailed description made with refer- This invention relates to telephone syslrnown manner.

ence to the accompanying drawings, in which Fig. 1 shows a common battery station A and a private branch exchange attendants cord circuit; and Fig. 2 shows a trunlrcircuit embodying the features of the invention, automatic switches schematically represented at S. and C and a machine switching subscribers line B. In reading the drawings, Fig. 1 is placed to the left of Fig. 2.

A call originating at station A will be traced to the station B, the connection including the private branch exchange attendants cord circuit, the trunk circuit L, selector S and connector C. r

A subscriber at A, to initiate a call removes the receiver from the switchhook, thereby causing the energization of line relay 10 which in turn causes the lighting of line lamp 12.

The private branch exchange attendant observing the illumination of the line lamp 12 inserts plug P of an idle cord circuit into the jack J" in which the subscribers line, corresponding toQthe lamp 12, terminates. The insertion of plug P into jack J causes the'operation of supervisory relay 14. Relay 1 1 in operating, prevents the illumination of supervisory lamp 16 atthis time. The insertion of plug P into jack J closes the local contact 25 of jack J wherenpon cut-oii' relay 11 operates to disconnect line relay 10 from the line circuit and to connect ground to the ,sleeve contact of jack J. Supervisory lamp 17 is thereupon lighted over a circuit from grounded battery through lamp 17, contact of supervisory relay 16, sleeve contacts of plug P" andjacir J and contact of cut-oft relay 11 to ground. The lamp 17 lighting at this time serves as a guard signal.

The attendant then actuates the talking key 18, thereby bridging the operators'telephone set across the tip and ring conductors of the cord so that she may now converse with the calling subscriber to ascertain the nature of the desired connection. Upon learning that a connection with the automatic subscriber at station E is desired, the attendant tests for an idle trunk in the well Assuming that trunk L-i-is' the first idle trunk encountered, the attendant. inserts contacts 1120f the dial D.

the terminals or the called line.

plug P into jack J of the idle trunk L. hen the plug P is fully inserted in jack J supervisory relay 16 operates over acircuit from grounded battery through the lower right hand winding of repeating coil 15, Winding of supervisory relay 16, lower normal contacts of ringing key 18, ring contacts of plug P and jack J lower left hand winding of repeating coil 1.00, bridging element 101, upper left hand winding of repeating coil 100, tip contacts of jack J and plug P upper normal contacts of ringing key 18, to ground through the upper right hand winding of repeating coil 15. Relay 16 in operating opens the circuit of and entinguishesll-amp 17.

When plug 5?? is inserted into jack J the normally closed contacts of the aek are opened, thereby removing the ringingrelay 1 30 from across the tip andring conductors ot the trunk. R'Vh'en the alternate contact 102 of jack J 2 is closed, slow releasing relay 10 1 operates.

transferring the holding oi the central oflice from thebridge above t-raced'to the The attendant now actuates the dial D to'di-al the desired con-tr al office number in the usual manner and then restores the dial key 111. As a co'nsequence of the operation of the dial '1),

the selector and connector, schematically represented at "S" and G, respectively, tunction in a manner wel-l known in'the attend as described in detail in reissue patent-to 'llewforth No. 135,901, dated April 13, 1915 to connect the {terminals ot the trunk L to it is believed unnecessary to enter into a. detailed description of these switches and their operations, since they do not enter into the present invention. F or the complete disclosure of such switches, reference may be had to the above mentioned patent.

The restoration of the dial key 111 again closes the holding bridge, including the winding of polarized relay 10'? and resistance element 108, across the central ofiice side of the repeating coil 1'00 to hold the cent-ralottice switches operated.

It willnow be assun'ied that the connection "to thesubscribers line 1B is completed and that the subscriber has *been signaled in the well known cnanner and as shown in the above menti-oned atent.

The closure of the con-' "tact 106 or ack J connects a holding bridge including the Winding of polarized relay ers line loop. Relay 113 in attracting its armatures, interchanges the tip and ring connections of relay 1114, thereby reversing the current over the trunk conductors and through the winding of polarized relay 107. This reversal of current causes the operation of polarized relay 107 whereupon relay 115 operates and then locks up in a circuitincluding the normal contact of relay 119 and the alternate Contact of relay 101. The

operation of relay 115 completes throughits right hand contact an operating circuit for the re ister magnet .117.

The magnet 11'? in operating, causes the register 118 to iiunction in manner well known in the art to register the outgoing call. When the register magnet 117 operates, it closes its left hand contact, causing relay 119 to operate. Relay 119 in attracting its right hand armature opens the looking circuit for relay 115, and'locks itself to ground on the alternate contact of relay 101. Relay 115 thereupon releases, causing the release of the register 118. At its outer left hand contact, relay 119 short circuits the polarized relay 107, thereby preventing this relay from again operating to cause the false operation of the register 118 which may be effected by the .called subscriber actuating the receiver switchhook in answering a call. It will be noted that by the attraction of the inner left hand a-rmatures of relay 119, polarized relay 120 is connected across-the central or'iice side of repeating coil 100, but :beingsh-ort circuited by contact 106 of jack J this relay does not operate at this time.

For the sake of simplicity, it-Will be assumed that the period of conversation has ended and that the calling subscriber has replaced the receiver .on the switchhook, thereby opening the circuit for supervisory relay 1 1 and causing supervisory lamp 16 to light over the sleeve circuit. Upon noting this signal, the attendant proceeds to take down the connection, and it will be assumed that the plug 1 is removed from jack d before the calledsubscriber at stationli has restoredthe receiver. The contacts and 102 of jack 5 are so adjusted that contact 106 is opened before contact 102, when the plug 1 is 'wi-thdrawn from the jack J so that the short circuit about the polarized relay 12 0 is removed before the circuit for relay 10 1 is opened. Relay 101 is made slow to release to turther insure the'operation of relay before its own release, thereby maintaining relay 119 operated. Relay 120 now operates on reversed battery from the selector S due to the fact that relay 113is still operated and in attraoti ng its armature establishes a locking circuit Iorneiay 119 independent of relay 104, so that when the latter relay deenergizes as result of the opening .otthe jack contacts 102, relay 119 will remain energized to hold polarized relay 107 short circuited until the called subscriber restores the receiver to the switchhook and again reverses the current over the trunk. This arrangement prevents a double registration which might occur it the attendant reinserted plug P into ack J before the called party at station B replaced the receiver on the switchhook at the termination of a call. The locking up of relay 115 before the register 118 operates as hereinbefore described, prevents double registration should the called sub.- scriber send out a preliminary pulse in removing the receiver from the switchhook in answer to a call. 3

Should the called subscriber replace the receiver on the switchhook before the attendant withdraws plug P from jack J relay 120 would not operate.

Vhen the operator Withdraws plug P from the ack J and the subscriber at B has replaced the receiver on the switchhook, relays 104 and 120 will release. Relay 120 in restoring, opens the locking circuit for relay 119, whereupon this relay retracts its armatures and restores the circuit to normal. The release of the automatic switches is accomplished in the same manner as described in the above mentioned patent. When the attendant withdraws plug P from jack J, the circuit for cutoff relay 11 is opened, whereupon this relay releases. and in retracting its armatures again connects the line relay 1.0 to the tip and ring conductors of the subscribers line. A, thereby conditioning the line for a new call. The circuits are now in normal condition, relay 14 having restored when the calling subscriber replaced the receiver on the switchhook at station A, and relay 16 being deenergized when the plug P was withdrawn from jack On a call originating at the automatic station B, the automatic switches will tunclion in the manner described in the above mentioned patent to seize an idle trunk L, whereupon ringing current is automatically connected to the trunk and passes through the repeating coil 100 to cause the operation of relay 130, which is bridged across the trunk by way of the normally closed contacts of jack Relay 130 in operating, causes the operation of slow-to-release relay 132' The operation of relay 132 causes the operation of relay 131 over a circuit including the alternate contact of relay 132 and the contact of relay 130. Relay 131 is slow to operate so as to permit relay 132 to be completely energized before relay 131 operates. Relay 131 in attracting its right hand armature, opens the energizing circuit for relay 132 which, after a short interval of time releases. Relay 131 in operating locks up over a circuit including the right hand normal contact of relay 132, left hand alternate contact of relay 131 and the normal contact of relay 104. Relay 130 remains operated so long as ringing current is connected to the trunkthe ringing current being disconnected when the attendant inserts plug P into jack J? as will more fully hereinai'ter appear. a V

The release of relay 132 while relay 131 is operated causes the lighting of lamp 133 over a circuit including the left hand con tact otrelayv 132, the right hand alternate contact of relay 132 the left-hand contactot relay 131 and the normal contact of relay 104, and the operation of relay 119 over a circuit including these same contacts. Relay 119, in operating, short circuits the polarized relay 107 in the same manner as hereinbefore described, thereby preventing the operation of the register 118 on an incoming call. I

Upon noting the illumination of lamp 133, the attendant proceeds to answer the call by inserting plug P? into jack J whereupon the ringing response relay 130is removed from the trunkand releases. I The closure of jack contact 106 connects resistance 108 across the condenser in the central oiiice side of repeating coil 100. This causes the operation of a relay in the ringing circuit which disconnects ringing current from the trunk in the manner set forth in the Newforth patent,

supra. "Upon the insertion of plug P into jack J relay 104 operates as hereinbefore de scribed. Relay 104 in operating, removes the locking ground from the winding of relay 131, whereupon relay 131 releases, opening the circuit for lamp 133, Lamp 133'thereupon extinguishes. Relay 104 in operating,

connects ground to the right hand winding of relay 119, therebymaintaming this relay operated, so as to prevent the register 113 from operating during the established connection. Should the attendant on a disconnect signal withdrawn the plug P from jack J? before the calling subscriber at B replaces the receiver on the switchhook.relay 1.20 will operate as hereinbefore described to maintain relay 119 operated and relay 107 short circuited, thereby rending the register ineffective to register incoming calls.

Froin the above descriptions, it is apparent that applicant has devised asystem wherein meansare provided. for discriminating between incoming and outgoing calls over a trunk circuit, whereby the message register associated with the trunk circuit is operated. to register only those calls outgoing from the private branch exchange attendants position and is rendered inellective to register calls incoming over the trunk to that position. Furthermore, as hereinbefore described, false operation of the register, due to the intervention of attendants or to the actuation of the receiver hook by 

